Leung said in an interview on TVB yesterday that the influx of tourists contributed to inflation of prices in the city. Those crossing from the mainland to the New Territories, where tourists usually shop for goods like formula milk, also 'disrupt the livelihood' of residents there, he said. 'The mainland government made the right decision in not expanding the individual visit scheme over the past five years,' Leung said.

The number of mainland tourists to Hong Kong has increased from 8.5 million in 2003, when the scheme started, to 28.1 million in 2011.

Leung's statement reflected the concerns of Shao Qiwei, director of the National Tourism Administration, at a meeting with tourism industry veterans last week, where Shao questioned whether Hong Kong's infrastructure could handle a further jump in numbers.

According to Joseph Tung Yiu-chung, executive director of the Travel Industry Council, Shao said it often took hours for mainlanders to cross the border into Hong Kong and that there were worries that the supply of hotel rooms was inadequate.

However, Leung was quick to add that if the local economy took a turn for the worse, he would bargain for the central government to extend the scheme to cover more cities.

The travel scheme used to cover only the four Guangdong cities of Dongguan, Zhongshan, Jiangmen and Foshan when it was introduced in 2003 as part of a liberalisation measure under the Closer Economic Partnership Arrangement. The number of eligible cities was broadened in 2007.

Despite Shao's concerns, industry experts said there was still room for more visitors, especially amid the global economic downturn.

Michael Li Hon-shing, executive director of the Federation of Hong Kong Hotel Owners, said the occupancy rate of top hotels slid from 98 per cent last December to less than 80 per cent this month due to a decrease in the number of business travellers. Government figures show another 41 hotels will be finished by 2014, and another 6,000 hotel rooms will be added to the market by 2016. 'If there is no increase in the number of tourists to match the bigger supply, what are we supposed to do?' Li said.

Simon Wong Ka-wo, chairman of the Hong Kong Food Council, said mainlanders spent HK$5 billion on food and beverages over the past year, about 5 per cent of the city's total spending. If the number of tourists dropped, restaurants in tourist districts would be hit, he said.

Over the past year, people have started to question the travel scheme's sustainability. Concern groups said tourist spending led to inflation, though others argued that mainland visitors were vital for economic growth and jobs generation. Tourism accounted for 6.2 per cent of the Hong Kong's economy in 2010, according to official figures.